Lightning-rod



(No Modem J. H. BRANDON.

LIGHTNING ROD.

Patented Jan. 9, 1883.

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UNITED STATES JOHN H. BRANDON, OF CHICAGO, ILLINOIS.

LIGHTNING-ROD.

SPECIFICATION forming part of Letters Patent No. 270,379, dated January 9, 1883,

Application filed May 26, 1882.

To all ywhom it may concern:

Beit known that I, JOHN H. BRANDON, ot' Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Lightning-Rods; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters ot' reference marked thereon, which form a part of this specification.

This invention relates to copper lightningrods, and has special reference to that class of such rods in which copper is used in a thin sheet in order to give a maximum surface. Copper in this form has been used heretofore, more commonly as a sheath or covering for an interior iron body or core ot' such size as to till the sheath, but has sometimes been used by itself, either in the form of a simple cylindrical tube or oi' a tube or sheet compressed to give longitudinal ilanges, either straight or spiral.

In the use of an iron rod or core immediately covered with sheet-copper the core adds great weight and expense to the rod without increasing its efficiency. Itis, moreover, found that by galvanic or other action both the copper and the iron are injured from contact or electric connection, the former being rendered brittle and the latter soon corroding or disintegrating so as to he greatly impaired in strength. In the use of the copper tubular rod without acore the rod lacks rigidity, and is liable to be collapsed and broken iny handling.

It is the object of this invention to provide a construction in a strictly copperrod, or in a rod in which the copper in sheet form is relied on as the conductor, whereby desirable strength and rigidity may be secured, and the copper may be held in the tubular form originally given it.

It also has for its object to provide suitablev means for connecting tubular sheet copper rods, so as to give necessary strength and continuity of the conducting-surfaces.

In the accompanying drawings, Figure l is a longitudinal section of a lightning-rod embodying my improvements. Fig. 2 is alongitudinal section of a modification ot' the same. Fig. 3 is a view in axial section'of one form of coupling or burr by which the rod-sections are (No model.)

joined, and Figl is a cross-section ot' the same on the line a; oc ot' Fig. 3.

In the drawings, A represents a section or length of a cylindrical tubular copper lightning-rod, and B a coupling connecting adjacent sections. For the purpose ot' holding the tube in its original iorm and of imparting thereto such rigidity as will insure it against collapsing, it is lilled with resin or other similar or suitable substance, C, which, while giving the stiffness required, allows it to be readily curved or bent to such shape as may be desired when fitting it to a building. The coupling B consists of plugs bwhich will generally be of inferior metal, secured within the ends ofthe tubes by rivets 1)',0r other suitable means, said plugs being fitted to join by nipple-and-socket construction or, it' both adjacent plugs be provided with nipples, a rightand-let't-threaded coupling-nut, B', may be used to join them, as shown in Fig. 3.

Fig. 2 shows a modification of my invention in which a relatively-small central metal core, D, is inserted within each length ot' copper rod and surrounded by ailling, C. Said core or rod D is also shown secured to the plugs b at opposite ends thereot'. By such connection the rod D serves to tie the couplings ofthe same length ot" rod together, and to givegreater tensile strength to a number of sections joined together, the copper shells and the rivets by which the couplings are secured thereto thus being relieved of the weight of the sections of rod below. As the resin or other lling C serves the purpose ofstifening the rod, the interior metal core will usually be required to resist only a tensile strain, and so may be very light and inexpensive; but it may be relied on to co-operate with the surrounding iilling to give rigidity `to the rod as a whole, and may therefore be of any size admitting the filling C between the sameand the outer shell. When such central rod is used the lling C should be practically a non-con-V ICO being,` secured to the coupling-plugs b b by a head at one end and a nut at the other, which permits due tension to be given to said rod after the plugs b are inserted in the ends of the copper tube. Then the plugs b of adjacent lengths of rod directly join by being made one with a threaded nipple and the other with acorrespondingly-threaded socket, care should be taken to provide that the copper tubes should intimately join one with the other, and to this end one may preferably extend beyond the shoulder ofthe plug, and may either meet or overlie the contiguous tube, as shown in Fig. 2, a close union being more readily made between said tubes it' theirjunction is not coincident with that of the plugs. If the plugs be both provided with nipples and joined by a coupling-nut, B', the latter is preferably covered with a copper sheath, C', which may similarly overlap the adjacent tubes, as shown in Fig. 3. By means ot a nut thus covered with copper continuity is given to the conducting-surface throughout the length of the rodwhen several lengths orsections are joined. This is not essential to my invention as enibodied in other features ot' construction, as a coupling-nut of inferior metal may be used without a copper covering, through which alone or through which and the plugs b-in this case uninsulated l'roin the copperthe current may tind continuous passage throughout the length of the coupled rod.

It'desired,the nietalcoresl) maybe threaded at their ends and srve as nipples for a coupling-nut; but in this casesaid nut should have its surface in electric connection with the adjacent copper tubes, and should be cut oft' from such connection with the core-rods-D. Bythe sectional ligure 4 the central part of the nut B is shown of angular form, to facilitate the use of a wrench therewith.

So far as the structural features of my invention areconccrned, it is immaterial whether the conducting,` substance be of copper or ot' other material, and as I know ot' no non-metallic substance which can be practically used as a filling` for the conducting-tube from which injury can result to the copper, the word non-metallic will serve as a compact expression for the substances meant to be eni bracedin the claim i'or such filling.

y I claim as my invention- 1. A section of lightning-rod consisting` ot' an exterior shell ofhigh conductivity provided with a non-metallic filling` and terminal couplings, substantially as described, and for the purposes set forth.

2. A section of lightning-rod consisting ol" an exterior shell of high conductivity, and a central metal rod materially smaller than the shell interior and insulated therefrom, substan tially as described. i

3. In a section ot' lightning-rod, the combination,with an outer conductingfshcll,ot'an insulated central metal core and coupling-plugs at the opposite ends ot' the rod-section joined by said metal core, substantially as described.

Il. In a section' ot' lightning-rod, the combination ot' an outer coiuluctingsbell, an inner non-conducting tlling, coupling-plugs at thc opposite ends ofthe rod-section, and a central metal tie-rod provided with a head at oneend and a nut at the other and passed through the plugs, substantially as described.

5. In combination with the copper tubes ol' a lightning-rod, a couplingynut provided with an outer covering' of copper, arranged to have intimate contact with the adjacent tubes for the purpose ot' giving;` continuity of conducting-surface, substantially as described.

In testimony that I claim the foregoing as my invention I at'tix my signature in presence ot' two witnesses.

JOHN II. BRANDON.

Witnesses M. E. DAYTON, W. U. ADAMS. 

